Guard for electric switches.



P. w. HORN.

GUARD FOR ELECTRIC SWITCHES. APPLICATION FILED APnlzz, 1916.

Patented Dec. 12, 1916.

2 SHEETS-SHEET 1.

F. W. HORN.

'GUARD FOR ELECTRIC SWITCHES.

APPLICATION mm APR. 22. 1am.

mmwd Dec. 112, 1916.

I filled d ill FlElDlElFtICK WILL]: HORN, F LESTER, PENNSYLVANIA.

GUARD JE'OlBt ELECTRIC SWITCHES.

To all whom it may concern:

Be it known that l, FREDERICK W. HORN, a citizen of the United States of America, residing at Lester, in the county of Delaware and State of Pennsylvania, have invented new and useful Improvements in Guards for Electric Switches, of which the a I closing the switch, or makingor breaking the circuit, for the purpose of protecting the til hand of the person using the switch, against contact with any part of the electric switch.

in many instances, the handle for operating "the switches of this character, is 1n an inaccessible location, and frequently the danger arises of a person having his hand in contact with conducting parts or live members of the switch, with resulting injury, and often death.

By the utilization of the shield or ard forming part of my invention, the possi ility of contact with'parts of the switch is eliminated, and the switch may be opened or;

closed with reasonable safety and certainty from danger, and the device is. rendered practically fool proof,

The invention consists in the combination and arrangement with the panel board and blade of a knife switch, of certain connecting parts associated with the guard or shield,

as Wlll be hereinafter more fully pointed out and claimed. In the accompanying, drawings 1 have illustrated one complete example of the physical embodiment of myinvention constructed according to the best mode'l have so far devised for the practical application of the principlesof my invention.

Figure 1 is a topplanJview pfa panel board showing the knife switch and fuse. and also showing'the adaptation thereto of my invention, the switch being shown as closed. Fig. 2 is a view similar to Fig. .1,

.but-with the knife switch opened. Fig. 3'is a diagrammatic front elevation view showing parts of the invention in dotted lines. Fig. l is a perspective view of a portion of the invention oing the coeetion be Specification of Letters Patent.

Patented lDee, l2, rare.

application filed April 22, 1916. serial Ito. 923W.

tween the knife bar, and'the shield or guard.

Fig. is a view showing the flexible joint between the shield or guard and the-panel board. Fig. 6 is a view partly in section showing the connection etween the guard plate or shoulder, and the knife bar.

In the preferred embodiment of my invention, as shown in the drawings, T have illustrated the panel board 1 of common type which is secured in proper position, as usual,

and in connection with the board a fuse 2 is illustra ed as supported in the spring arms 3-3. he pivot bracket or plate 4 and the sheath 5 for the knife 6, which is pivoted to the plate 4 at 7, are all of usual and stand, ard construction, and it will be understood that the knife blade or plate 6 of the switch may swing on its pivot pin 7, as'usual.

In the exemplificationof my inventioml have illustrated a panel board in which four switches are employed, the knives or blades 6, 8, 9 and 9 all being similar in construction and operation, and these four blades are secured to the knife bar 10 as indicated at ll. The bar is arranged either in a vertical or horizontal position, depending upon thelocation of the panel board, but preferably as shown in the drawings, this bar is vertical, and has attached thereto the horizontally extending blades of the four knife switches. It will. readily be seen that the number of switches may be increased or decreased as desired, by lengthening or shortening the bar 10, and I contemplate the use of a different number of switches, as well as the number illustrated in the drawings. Each of the knife blades has a pivot independent of the others but, of course, the pivot pins are all alined so that the blades and bar may swing from the same point. The whole front of the switch device is covered by the wooden panel or board 12, which forms a shield or guard against contact bv any ob' ject with the parts between said board and the panel board.

Preferably, the board 12 is of wood, in order to obtain lightness, but it could be of other nonconducting material, and the shield or plate is pivoted to the panel board 1 through the utilization of a fiexibleconnection comprising the link 13 pivoted at 14: to a stud 15, which is fixed to the panel 1.

- and the other end-of this link is pivoted at 16 to a stud 17 which is provided with a threaded end throu a l wt in the shield 12, and this threaed end is in? by a nut 18, whichsecures the parts together. In this manner, a,double hinge is provided betweenthe panel board and the guard plate, so that the guardplate may swing in close to the panel board when the switches are opened, but stand out away from the panel when the switches are closed, in order to clear the supporting plates for the knife switches, and also to render the movement of the knife blades and guard plate free and easy when the switches are to be opened.

The knife bar 10 and the guard plate 12 are connected together at two points by a hinged joint, made up of a perforated stud 19 which has a threaded end and is clamped I to the guard plate 12 by a nut 20, and a bolt or screw 21 is threaded into the insulated knife bar 10, and the perforated end 22 of this screw is pivoted to the stud 19 at 23. The pair of hinged joints between the guard plate and the knife bar are spaced apart at proper intervals, and it will'thus be seen that the knife blades provide .four pivot joints. There are two hinged joints between the knife bar and the guard plate,

and one double joint between the guard plate and the panel board. By means of these pivot joints, a suitable connection is made for all the connected parts, and although there is sufficient flexibility to permit facile movement of the parts, it will be seen that there is suflicient rigidity to insure a workmanlike arrangement of the parts to prevent disarrangements or displacement of v the members. In Fig. 2, the movement of the parts is indicated by the arrows, the switch having been opened by swinging the guard Copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0.

plate on. the pivot pins 7, and the double hinge joints 14 and 16. A knob 24 is attached to the guard plate 12 and the plate may be swung upon its hinges by a pull or push on the knob when it is grasped by the fingers, as usual.

From the above description taken in connection with my drawings it is evident that I have provided an efiicien't device which is durable, simple in construction and operation, and comparatively inexpensive in cost. for performing the functions of a perfect device of this character.

What I claim is:

1. The combination in a knife switch including the panel board and av plurality of knife blades forming part of the switch, of a guard plate covering the switches, a double hinge joint between said guard plate and panel board, and a hinge joint between the pivoted knife blades and the guard plate.

2. The combination in a safety device for knife switches, comprising a panel board and knife supporting brackets, a plurality of knife blades pivoted in the brackets, an in sulated knife bar attached to the blades, a guard plate pivoted to the bar, and a hinge joint between the guard plate and the panel board.

3. The combination with the pivoted blade of a knife switch, of a guard plate pivotally connected to the blade, a panel board supporting the switch, and a hinge joint between the panel board and the guard plate.

In testimony whereof I afiix my signature.

FREDERICK WM. HORN.

Commissioner of Patents, 

